Clinical Workflow Integration for ctDNA Testing and Patient Communication

Dr. Teplinsky addresses where ctDNA and MRD testing fit within the patient care continuum, noting that value isn't uniform across disease stages or tumor types. The strongest signal currently exists in the post-treatment surveillance setting, where tumor-informed assays can identify patients at higher recurrence risk before disease becomes visible on imaging.

She emphasizes that the central challenge involves determining clinical actionability: can intervention on positive ctDNA before imaging-detected disease improve outcomes? Colorectal cancer has the most mature data, with other tumor types catching up. She characterizes ctDNA primarily as a risk stratification and monitoring tool, with the field still determining how to act on this information.

In her breast and gynecologic oncology practice, she lacks robust action points for routine testing given uncertainty about appropriate responses to results. She primarily uses ctDNA within clinical trials, encouraging trial enrollment, though she occasionally tests high-risk patients who specifically want recurrence risk information even without actionable next steps, emphasizing the importance of discussing benefits, limitations, and unknowns to support informed patient decision-making.

Regarding molecular relapse impact on surveillance, she explains that positive ctDNA typically triggers immediate imaging to assess for radiographic evidence of relapse. If imaging remains negative, questions arise about appropriate scan frequency, with her practice generally defaulting to approximately every 3 months absent robust supporting data.

Dr. Grivas addresses communicating results without triggering anxiety, explaining his approach of describing imaging limitations (requiring lesions to reach detectable size) versus ctDNA's ability to detect molecular residual disease at more microscopic levels before imaging-threshold disease develops. He emphasizes discussing test timing relevance, prognostic versus predictive implications, and ensuring tests are used judiciously where actionable data exists, citing the IMvigor011 trial in immunotherapy-naïve bladder cancer patients with high-risk pathologic staging as an example where serial ctDNA monitoring informs adjuvant immune checkpoint inhibitor decisions and timing.